Switch override containing block sizes to use LayoutRareData

third_party/WebKit/Source/core/layout/LayoutBox.h

 /*
  * Copyright (C) 1999 Lars Knoll (knoll@kde.org)
  *           (C) 1999 Antti Koivisto (koivisto@kde.org)
  * Copyright (C) 2003, 2006, 2007 Apple Inc. All rights reserved.
  *
  * This library is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Library General Public
  * License as published by the Free Software Foundation; either
  * version 2 of the License, or (at your option) any later version.
  *
@@ skipping 43 matching lines @@
     ApplyNonScrollOverflowClip
 };
 
 using SnapAreaSet = HashSet<const LayoutBox*>;
 
 struct LayoutBoxRareData {
     WTF_MAKE_NONCOPYABLE(LayoutBoxRareData); USING_FAST_MALLOC(LayoutBoxRareData);
 public:
     LayoutBoxRareData()
         : m_spannerPlaceholder(nullptr)
+        , m_overrideLogicalContentWidth(-1)
         , m_overrideLogicalContentHeight(-1)
-        , m_overrideLogicalContentWidth(-1)
+        , m_overrideContainingBlockContentLogicalWidth(-2)
+        , m_overrideContainingBlockContentLogicalHeight(-2)
         , m_percentHeightContainer(nullptr)
         , m_snapContainer(nullptr)
         , m_snapAreas(nullptr)
     {
     }
 
     // For spanners, the spanner placeholder that lays us out within the multicol container.
     LayoutMultiColumnSpannerPlaceholder* m_spannerPlaceholder;
 
+    LayoutUnit m_overrideLogicalContentWidth;
     LayoutUnit m_overrideLogicalContentHeight;
-    LayoutUnit m_overrideLogicalContentWidth;
+
+    // These two can be set to -1 to override the containing block size to be
+    // undefined, so we use -2 to indicate that no override has been set.

[jfernandez, 2016/08/22 14:56:03]

I'm not sure whether we need such a difference between "unset" and "undefined".
Perhaps I'm missing something, but I'd always thought when override wasn't set
it meant it was "undefined".

+    LayoutUnit m_overrideContainingBlockContentLogicalWidth;
+    LayoutUnit m_overrideContainingBlockContentLogicalHeight;
 
     LayoutUnit m_pageLogicalOffset;
     LayoutUnit m_paginationStrut;
 
     LayoutBlock* m_percentHeightContainer;
     // For snap area, the owning snap container.
     LayoutBox* m_snapContainer;
     // For snap container, the descendant snap areas that contribute snap
     // points.
     std::unique_ptr<SnapAreaSet> m_snapAreas;
@@ skipping 1131 matching lines @@
         || breakValue == BreakLeft
         || breakValue == BreakPage
         || breakValue == BreakRecto
         || breakValue == BreakRight
         || breakValue == BreakVerso;
 }
 
 } // namespace blink
 
 #endif // LayoutBox_h